Fig. 2.

Percentage ¹³C and ¹⁵N uptake by Trichodesmium trichomes at 6 time points and corresponding NanoSIMS images. (A) Percentage ¹³C and ¹⁵N uptake at 5 time points in Trichodesmium cells analyzed by NanoSIMS. Along the x axis are representative NanoSIMS images of ¹⁵N enrichment in ≈2.5 cells at (B) 0 h, (C) 2 h, (D) 4 h, (E) 8 h, and (F) 24 h. Along the y axis are corresponding images of ¹³C enrichment at (G) 0 h, (H) 2 h, (I) 4 h, (J) 8 h, and (K) 24 h. Data points represent average values for individual cells measured along a single trichome by NanoSIMS. [Scale bar, 1 μm; image enrichment scale ranges from 0 to 5% uptake (N), and 0 to 30% uptake (C), moving from black-blue-red-yellow-white.]